Update python/tskit/tables.py

Co-authored-by: Peter Ralph <petrel.harp@gmail.com>

Author: hyanwong

python/tskit/tables.py

@@ -4028,7 +4028,7 @@ def concatenate(
     ):
         """
         Concatenate another table collection to the right of this one. This {meth}`shift`s the
-        other table coordinate rightwards, then repeatedly calls {meth}`union` with
+        other table coordinate rightwards, then calls {meth}`union` with
         the provided ``node_mapping``. If no node mapping is give, the two table
         collections must have the same number of samples, and those are treated
         (in numerical order) as shared between the two table collections.